The present invention relates to a spunbonded nonwoven made of thermoplastic material. The spunbonded nonwoven has filaments having a filament diameter of less than 2 μm, the filaments being made from bursted fibers.
A device for producing a nonwoven is known from European Patent Application 0 724 029 B1, in which a Laval nozzle is positioned downstream of a spinning nozzle. The thermoplastic material coming out of the spinning nozzle is drawn through the Laval nozzle using cold air, the air forming a laminar flow. Positioning a spinning nozzle and a Laval nozzle one behind the other is also known from European Patent Application 0 339 240 A2. In this case, however, a hot inert gas is used for cooling and stretching the fibers, the polyphenylene sulfide of the fibers used burst into individual filaments. A device is known from WO 01/00909 A1, which has a spinning nozzle and a Laval nozzle connected downstream. According to WO 01/00909 A1, a pressure difference over the Laval nozzle with simultaneous overpressure in the fiber ensures that the fiber bursts. A plurality of filaments is to result from one fiber.
The object of the present invention is to expand the technology and fields of application of bursted fibers.